1. Field of Invention
The invention relates generally to communications networks and in particular to a method and system for allocating protection path resources in a communications network.
2. Description of Related Art
In existing communications networks, protection paths are provided for one or more working paths in the event the working path fails. A variety of protection topologies exist and include assigning a single protection path for each working path (referred to as 1:1) or multiple working paths sharing a protection path (referred to as 1:N). Protection topologies also vary depending on the network topology and may be implemented in linear, ring or mesh configurations. Protection mechanisms may be implemented at the link level such as automatic protection switching (APS) or at higher levels such as ring level bi-directional line switched ring (BLSR).
In many situations, there is a desire to limit the amount of protection path bandwidth while still providing adequate protection. This is the motivation behind 1:N protection. Whenever protection path bandwidth is increased, this reduces available bandwidth for working paths. Thus, there is a need for a method of allocating protection path resources that limits increases in protection path bandwidth.